Under-screen biometric identification apparatus and electronic device

ABSTRACT

Provided are an under-screen biometric identification apparatus and an electronic device. The under-screen biometric identification apparatus includes: a lens disposed under a display screen for receiving an optical signal formed by reflection of a human finger on the display screen, where the optical signal is used to detect biometric information of the finger; a lens barrel, where the lens is fixed in the lens barrel; and a support, where the support is connected to the lens barrel by means of threaded connection for supporting the lens barrel. An under-screen biometric identification apparatus and an electronic device provided in embodiments of the present application can improve the efficiency of under-screen biometric identification.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/563,854, filed on Sep. 7, 2019, which is a continuation of U.S.patent application Ser. No. 16/104,205, filed on Aug. 17, 2018. The U.S.patent application Ser. No. 16/104,205 claims priority of Chinese PatentApplication No. 201821077979.2 entitled “UNDER-SCREEN BIOMETRICIDENTIFICATION APPARATUS AND ELECTRONIC DEVICE” filed on Jul. 6, 2018 toPatent Office of the People's Republic of China, the entire content ofwhich is incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present application relate to the field of biometricidentification, and more particularly, to an under-screen biometricidentification apparatus and an electronic device.

BACKGROUND

With rapid development of a mobile phone industry, biometricidentification technology has received more and more attention frompeople, and practical usage of more convenient under-screen biometricidentification apparatus, such as under-screen fingerprintidentification technology, has become a popular requirement.

At present, under-screen optical fingerprint identification technologymainly includes under-screen optical fingerprint identificationtechnology based on a periodic micro-hole array and under-screen opticalfingerprint identification technology based on an integrated micro lens.The former optical fingerprint identification technology is susceptibleto Moire fringes, and an optical fingerprint identification module needsto be attached under an OLED screen, while the process is complicated. Afingerprint identification module of the latter under-screen opticalfingerprint identification technology is integrated, and thereforeprecision requirement of the entire optical fingerprint identificationmodule is very high in a mass production process, whereas commonprocessing technology is basically insufficient to meet actual needs.Due to the existence of the above various problems, the efficiency ofunder-screen biometric identification is affected.

Therefore, how to improve the efficiency of under-screen biometricidentification has become a technical problem to be solved.

SUMMARY

Provided are an under-screen biometric identification apparatus and anelectronic device, which could improve the efficiency of under-screenbiometric identification.

In a first aspect, provided is an under-screen biometric identificationapparatus, including a lens disposed under a display screen forreceiving an optical signal formed by reflection of a human finger onthe display screen, where the optical signal is used to detect biometricinformation of the finger; a lens barrel, where the lens is fixed in thelens barrel; and a support, where the support is connected to the lensbarrel by means of threaded connection for supporting the lens barrel.

In some possible implementations, a dispensing structure is formedbetween the lens barrel and the support, and the threaded connectionbetween the lens barrel and the support is fixed by means of dispensingin the dispensing structure.

In some possible implementations, the dispensing structure includes: afirst step structure formed by an upper surface of the support extendingdownward in a peripheral area of a threaded hole.

In some possible implementations, the lens includes an aspherical lensor an aspherical lens group.

In some possible implementations, a lower surface of the support extendsdownward in a peripheral area of the threaded hole to form a firstconvex structure, and the lens is mounted in the first convex structure.

In some possible implementations, the lower surface of the support isprovided with a second convex structure formed between the first convexstructure and an edge of the support.

In some possible implementations, an upper surface of the lens barrelextends inward at a barrel opening to form a third convex structure, andthe third convex structure is used for fixing the lens.

In some possible implementations, an upper surface of the lens barrel isprovided with a bevel angle formed by chamfering processing at thebarrel opening such that an inner diameter of the lens barrel at theupper surface is greater than an inner diameter of the lens barrel atthe third convex structure.

In some possible implementations, an inner side surface of the lensbarrel is provided with a second step structure formed under the thirdconvex structure, and the lens is fixed in the lens barrel through thesecond step structure.

In some possible implementations, an outer side surface of the lensbarrel is provided with a fourth convex structure formed under the thirdconvex structure, and an external thread is formed on the fourth convexstructure.

In some possible implementations, the under-screen biometricidentification apparatus further includes an imaging chip disposed underthe lens barrel for imaging based on an optical signal passing throughthe lens, where a distance between the lens and the imaging chip isadjusted by rotating the lens barrel.

In some possible implementations, a distance between an optical centerof the lens and an upper surface of the imaging chip is equal to animaging distance of the lens.

In some possible implementations, the upper surface of the lens barrelextends outward in an edge area to form at least one fifth convexstructure, and the fifth convex structure is used for rotating the lensbarrel to adjust a distance between the lens and the imaging chip.

In some possible implementations, the under-screen biometricidentification apparatus further includes an optical filter, where theoptical filter is located between the lens and the imaging chip.

In some possible implementations, the optical filter is fixed on theupper surface of the imaging chip.

In some possible implementations, the optical filter is fixed in thelens barrel.

In some possible implementations, an edge area of a lower surface of thelens extends downward to form a convex ring structure, a lower surfaceof the convex ring structure is in contact with the filter, and an outerside edge area of the convex ring structure is fixedly connected to anupper surface of the filter in an adhesive attaching and fixing method.

In some possible implementations, the under-screen biometricidentification apparatus further includes a micro lens array fixed on anupper surface of the imaging chip, where the micro lens array is usedfor imaging an optical signal passing through the lens to imaging pixelunits of the imaging chip.

In some possible implementations, each of the imaging pixel units of theimaging chip corresponds to one micro lens in the micro lens array.

In some possible implementations, the micro lens in the micro lens arrayis a hemispherical lens, the imaging pixel unit is a polygon, and adiameter of the hemispherical lens is a length of a long side of thepolygon.

In some possible implementations, the under-screen biometricidentification apparatus further includes a flexible printed circuit,where the imaging chip is fixed on an upper surface of the flexibleprinted circuit, and a lower surface of the support and the uppersurface of the flexible printed circuit are fixedly connected in an edgearea of the imaging chip.

In some possible implementations, the support is provided with a venthole for adjusting an atmospheric pressure intensity of an internalspace formed by the support and the flexible printed circuit.

In some possible implementations, the under-screen biometricidentification apparatus further includes a steel plate, where the steelplate is fixed on a lower surface of the flexible printed circuit.

In some possible implementations, the under-screen biometricidentification apparatus further includes a fixing support, where thesupport is fixed under the display screen by the fixing support suchthat a distance between the upper surface of the display screen and theoptical center of the lens satisfies an imaging condition.

In some possible implementations, the under-screen biometricidentification apparatus is applied to an electronic device, the fixingsupport is a middle frame of the electronic device, and the middle frameis used for supporting the display screen.

In some possible implementations, the middle frame and the support arefixed by any one of the following mounting methods: a screw mounting andfixing method, and an adhesive attaching and fixing method, a weldingand fixing method and a coupling and fixing method.

In some possible implementations, the middle frame is provided with ahole, the lens barrel is at least partially accommodated in the hole,and there is a gap between an outer side of the lens barrel and an innerside of the hole.

In some possible implementations, an upper surface of the middle frameis provided with a bevel angle formed by chamfering processing at anedge of the hole, and the bevel angle enables a width of the hole on theupper surface of the middle frame to be larger than a width of the holeon the lower surface of the middle frame.

In some possible implementations, the upper surface of the middle frameis provided with a third step structure formed in an edge area of thehole.

In some possible implementations, a lower surface of the middle frameextends downward in a peripheral area of the hole to form a fifth convexstructure, and the support is mounted in the fifth convex structure.

In some possible implementations, a lower surface of the middle frameextends upward in an edge area of the hole to form a groove structure,and the support is mounted in the groove structure.

In some possible implementations, the under-screen biometricidentification apparatus further includes a foam, where the foam isdisposed between an upper surface of the support and a lower surface ofthe middle frame.

In a second aspect, provided is an electronic device, including theunder-screen biometric identification apparatus of the first aspect.

In some possible implementations, the electronic device further includesa display screen, where the under-screen biometric identificationapparatus is disposed under the display screen such that a distancebetween an upper surface of the display screen and an optical center ofa lens in the under-screen biometric identification apparatus satisfiesan imaging condition.

On one hand, threaded connection between a support and a lens barrel inembodiments of the present application enables desired optical imagingto be achieved by focusing, in the process of assembling an under-screenbiometric identification apparatus 140, thereby reducing requirements ofprocessing technology, and also solving a problem of batch yield of anintegrated module in a production assembly process and a problem that anoptimal focal length of the integrated module cannot be preciselyaligned, and further, improving the efficiency of under-screen biometricidentification.

On the other hand, an optical fingerprint identification module isavoided to be attached to a lower surface of a display screen, and onlythe under-screen biometric identification apparatus 140 needs to bedisposed under the display screen, for example, the lens is disposed onthe display screen, thereby effectively simplifying an installationprocess of the under-screen biometric identification apparatus 140,improving a batch yield during the installation process of theunder-screen biometric identification apparatus 140, and reducing adamage rate in a replacement process of the under-screen biometricidentification apparatus 140, and further, reducing costs effectively.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view of a mobile terminal to which thepresent application is applicable.

FIG. 2 is a partial schematic cross-sectional view of the mobileterminal shown in FIG. 1 taken along A′-A′.

FIG. 3 is an oriented view of an under-screen biometric identificationapparatus.

FIG. 4 is an oriented view of a support in the under-screen biometricidentification apparatus shown in FIG. 3.

FIG. 5 is an oriented view of a lens barrel in the under-screenbiometric identification apparatus shown in FIG. 3.

FIG. 6 is a partial schematic cross-sectional structural view of theunder-screen biometric identification apparatus shown in FIG. 3 takenalong B′-B′.

FIG. 7 is an oriented view of an under-screen biometric identificationapparatus according to an embodiment of the present application.

FIG. 8 is an oriented view of a filter, an imaging chip, a circuitboard, and an image processor in the under-screen biometricidentification apparatus shown in FIG. 7.

FIG. 9 is a partial schematic cross-sectional structural view of theunder-screen biometric identification apparatus shown in FIG. 7 takenalong C′-C′.

FIG. 10 is a schematic structural view of a filter in a lens barrelaccording to an embodiment of the present application.

FIG. 11 is a schematic structural view of an imaging chip having a microlens array according to an embodiment of the present application.

FIG. 12 is an oriented view of an upper surface of a support of anunder-screen biometric identification apparatus attached with a foamaccording to an embodiment of the present application.

FIGS. 13 to 18 are schematic structural views of an under-screenbiometric identification apparatus located under a display screenaccording to embodiments of the present application.

DETAILED DESCRIPTION

The technical solutions in embodiments of the present application willbe described hereinafter in conjunction with the attached drawings.

As a smart terminal enters an era of full screen, a biometric capturingarea on the front of an electronic device is squeezed by the fullscreen, and therefore, an under-display or under-screen biometricidentification technology has gained an increasing attention. Theunder-screen biometric identification technology refers to mounting anunder-screen biometric identification apparatus (such as a fingerprintidentification module) under a display screen, thereby realizing abiometric identification operation inside a display area of the displayscreen, without setting a biometric capturing area in an area on thefront of an electronic device other than the display area.

The under-screen biometric identification technology may include anunder-screen optical biometric identification technology, anunder-screen ultrasonic biometric identification technology, or othertypes of under-screen biometric identification technologies.

Taking the under-screen optical biometric identification technology asan example, the under-screen optical biometric identification technologyuses light returned from a top surface of a display component of adevice for fingerprint sensing and other sensing operations. Thereturned light carries information of an object (e.g., a finger) incontact with the top surface, and a particular optical sensor modulelocated under a display screen is implemented by capturing and detectingthe returned light. The particular optical sensor module may be designedto achieve desired optical imaging by properly configuring an opticalelement for capturing and detecting a returned light.

It should be understood that technical solutions of embodiments of thepresent application can be applied to various electronic devices, andmore particularly, to an electronic device having a display screen, forexample, portable or mobile computing devices such as a smart phone, anotebook computer, a tablet computer and a game device, and otherelectronic devices such as an electronic database, an automobile and anautomated teller machine (Automated Teller Machine, ATM), which is notlimited in the embodiments of the present application.

It should also be understood that the technical solutions of theembodiments of the present application can perform other biometricidentification in addition to fingerprint identification, for example, aliving body identification and the like, which is not limited in theembodiments of the present application.

FIG. 1 and FIG. 2 are schematic views showing an electronic device 100to which an under-screen biometric identification apparatus isapplicable. FIG. 1 is schematic front view of an electronic device 100to which an under-screen biometric identification apparatus isapplicable, and FIG. 2 is a partial schematic cross-sectional structuralview of the electronic device 100 shown in FIG. 1 taken along A′-A′.

As shown in FIG. 1 and FIG. 2, the electronic device 100 may include adisplay screen 120 and an under-screen biometric identificationapparatus 140; and the display screen 120 has a display area 102, andthe under-screen biometric identification apparatus 140 is disposedunder the display screen 120.

The display screen 120 may be a self-emitting display screen thatemploys a self-emitting display unit as a display pixel. For example,the display screen 120 may be an organic light-emitting diode (OrganicLight-Emitting Diode, OLED) display screen or a micro light-emittingdiode (micro-LED) display screen. In other alternative embodiments, thedisplay screen 120 may also be a liquid crystal display (Liquid CrystalDisplay, LCD) screen or other passive light-emitting display screens,which is not limited in the embodiments of the present application.

The display screen 120 may be specifically a touch display screen, whichmay not only display a screen but also detect a touch or press operationof a user, thereby providing the user with a human-machine interactioninterface. For example, in an embodiment, the electronic device 100 mayinclude a touch sensor, and the touch sensor may be specifically a touchpanel (Touch Panel, TP), which may be disposed on a surface of thedisplay screen 120, or may be partially integrated or entirelyintegrated into an interior of the display screen 120 to form a touchdisplay screen.

The under-screen biometric identification apparatus 140 may be anoptical under-screen biometric identification apparatus, which mayinclude an optical biometric sensor with an optical sensing array, suchas an optical fingerprint sensor; and the optical sensing array includesa plurality of optical sensing units, and an area where the opticalsensing array is located is a biometric capturing area of theunder-screen biometric identification apparatus 140, and the opticalsensing units are used for capturing fingerprint characteristicinformation (such as fingerprint image information) of a user.

The under-screen biometric identification apparatus 140 may be disposedat least in a partial area under the display screen 120 such that thebiometric capturing area (or sensing area) of the under-screen biometricidentification apparatus 140 is at least partially located in thedisplay area 102 of the display screen 120.

As shown in FIG. 1, the biometric capturing area 130 is located in thedisplay area 102 of the display screen 120. Therefore, when a user needsto unlock the electronic device or perform other biometric verification,a biometric input operation can be implemented merely by pressing afinger on the biometric capturing area 130 located on the display screen120. Since biometric capturing detection can be implemented inside thedisplay area 102 of the display screen 120, a front surface of theelectronic device 100 in the above structure does not need to reservespace to set a fingerprint button (such as a Home button), so that afull screen solution can be adopted. That is, the display area 102 ofthe display screen 120 can be substantially extended to the entire frontsurface of the electronic device 100.

In the biometric identification process, the display screen 120 adoptingthe OLED display screen is taken as an example, the display screen 120has OLED display units distributed in an array, and the under-screenbiometric identification apparatus 140 can utilize an OLED display unit(i.e., an OLED light source) of the OLED display 120 located in thebiometric capturing area 130 as an excitation light source for biometricdetection and identification. Of course, it should be understood that inother alternative implementations, the under-screen biometricidentification apparatus 140 may also provide an optical signal forbiometric detection and identification by adopting an internal lightsource or an external light source; and in this case, the under-screenbiometric identification apparatus can be applied not only to aself-emitting display screen such as an OLED display screen, but also toa non-self-emitting display screen such as a liquid crystal displayscreen or other passive light-emitting display screens. Moreover, theoptical sensing array of the under-screen biometric identificationapparatus 140 may be specifically a photo detector array (or referred toas a photodetector array) including a plurality of photo detectors orphotodetectors distributed in an array, and the photo detectors orphotodetectors may server as the optical sensing units as describedabove.

When a finger touches, presses, or approaches (collectively referred toas pressing for convenience of description) the biometric acquiring area130, light emitted by the display unit of the biometric capturing area130 is reflected by the finger to form reflected light. The reflectedlight may carry fingerprint characteristic information of a user'sfinger. For example, after the light is reflected by a fingerprint onthe surface of the user's finger, since the reflected light of afingerprint ridge is different from that of a fingerprint valley, thereflected light carries fingerprint information of the user. Thereflected light is returned to the display screen 120, received by aphotodetector array of the under-screen biometric identificationapparatus 140 underneath, and converted into a corresponding electricalsignal, i.e., a biometric detection signal. The electronic device 100can obtain biometric information of the user based on the biometricdetection signal, and can further perform biometric matchingverification, thereby completing identity verification of the currentuser so as to confirm whether the user has permission to perform acorresponding operation on the electronic device 100.

In other alternative embodiments, the under-screen biometricidentification apparatus 140 may also be disposed in an entire areaunder the display screen 120 so as to extend the biometric capturingarea 130 to the entire display area 102 of the display screen 120,thereby implementing full screen biometric identification.

It should be understood that in a specific implementation, theelectronic device 100 may further include a protective cover 110, theprotective cover 110 may be specifically a transparent cover such as aglass cover or a sapphire cover which is located on the display screen120 and covers a front surface of the electronic device 100, and thesurface of the protective cover 110 may also be provided with aprotective layer. Therefore, in an embodiment of the presentapplication, the so-called finger pressing the display screen 120 mayactually refer to the finger pressing the cover plate 110 on the displayscreen 120 or covering a surface of the protective layer of the cover110.

In one implementation, the under-screen biometric identificationapparatus 140 may transmit light to a sensing array by using a periodicmicro-hole array. This requires an optical fingerprint identificationmodule to be bonded under an OLED screen, which is complicated andcostly. In another implementation, the under-screen biometric device 140may transmit light to a sensing array by using an integrated micro lens,which refers to designing the micro lens and the sensing array as awhole so as to further form an integrated module. Since the integratedmodule has very high precision requirements in a mass productionprocess, a common processing technology is substantially insufficient tomeet actual needs.

In order to solve the above technical problem, embodiments of thepresent application provide an improved technical solution.Specifically, the under-screen biometric identification apparatus 140adopts a lens to transmit light onto a sensing array. More specifically,the under-screen biometric identification apparatus 140 may include asupport and a lens barrel having a built-in lens, where the lens isdisposed under a display screen for receiving an optical signal formedby reflection of a human finger on the display screen, and the opticalsignal is used to detect biometric information of the finger. Forexample, the optical signal may be reflected light carrying fingerprintinformation of the finger as described above, and may be used to detectthe fingerprint information of the finger. The support is connected tothe lens barrel by means of threaded connection for supporting the lensbarrel.

It should be noted that, in certain scenarios, the lens in theembodiment of the present application needs to be configured as anelement or a device for modulating light that is more accurate in anassembling process and smaller in volume than a front camera forphotographing, so as to meet precise focusing requirements of anunder-screen optical fingerprint.

Compared with the former implementation manner (using a periodicmicro-hole array to transmit light onto a sensing array), the technicalsolution of the embodiment of the present application avoids bonding anoptical fingerprint identification module to a lower surface of adisplay screen, and only requires to dispose an under-screen biometricidentification apparatus 140 under the display screen. For example, thelens is disposed under the display screen, which effectively simplifiesa mounting process of the under-screen biometric identificationapparatus 140, improves a batch yield in the process of mounting theunder-screen biometric identification apparatus 140, reduces a damagerate in a replacement process of the under-screen biometricidentification apparatus 140, and further, reduces the cost effectively.

Compared with the latter implementation manner (using an integratedmicro lens to transmit light onto a sensing array), threaded connectionbetween a support and a lens barrel in the technical solution of theembodiment of the present application enables desired optical imaging tobe achieved by focusing in a process of assembling the under-screenbiometric identification apparatus 140, thereby reducing requirements ofa processing technology, effectively solving a problem of high precisionrequirements in a mass production process of an integrated module, andalso solving a problem of a batch yield of an integrated module in aproduction assembly process and a problem that an optimal focal lengthof the integrated module cannot be precisely aligned, and further,improving the efficiency of under-screen biometric identification.

An under-screen biometric identification apparatus 300 according to anembodiment of the present application will be clearly described belowwith reference to FIGS. 3 to 5. It should be noted that, in theembodiments of the present application, like reference numeralsrepresent like components, and detailed description of the likecomponents is omitted in different embodiments for the sake of brevity.

FIGS. 3 to 13 show schematic views of an under-screen biometricidentification apparatus 200, where FIG. 3 is an oriented view of anunder-screen biometric identification apparatus 200. FIG. 4 is anoriented view of a support 230 in the under-screen biometricidentification apparatus 200 shown in FIG. 3. FIG. 5 is an oriented viewof a lens barrel 230 in the under-screen biometric identificationapparatus 200 shown in FIG. 3. FIG. 6 is a partial schematiccross-sectional structural view of the under-screen biometricidentification apparatus 200 shown in FIG. 3 taken along B′-B′.

As shown in FIGS. 3 to 6, the under-screen biometric identificationapparatus 200 may include a lens 210, a lens barrel 220 and a support230. The lens 210 is disposed under a display screen, and is used forreceiving an optical signal formed by reflection of a human finger onthe display screen. For example, after light emitted by the displayscreen is reflected by a finger on the display screen, a portion ofreflected light may be received by the lens 210. The lens 210 is fixedin the lens barrel 220. The support 230 is connected to the lens barrel220 by means of threaded connection for supporting the lens barrel 220.

The display screen may be the display screen shown in FIG. 1 and FIG. 2.For related description, reference may be made to the foregoingdescription of the display screen 120, and no further details areprovided herein for brevity.

Optionally, in an embodiment of the present application, the lens 210may include an aspherical lens or an aspherical lens group to reduceimaging distortion of a fingerprint image.

It should be noted that a focal length of the aspherical lens or theaspherical lens group may be smaller than a focal length of a frontcamera for photographing, or the lens 210 is a macro lens to meetrequirements of under-screen fingerprint identification. For example, afocal length of the macro lens may range from 0.5 mm to 1.8 mm. Itshould be noted that the range is only an exemplary range of the gap,and the embodiment of the present application is not limited thereto.For example, the focal length of the macro lens may also be 2 mm.

In the process of assembling the under-screen biometric identificationapparatus 200, desired optical imaging can be achieved by anauto-focusing machine adjusting a height of the lens barrel 220.

In order to ensure that the height-adjusted lens barrel 220 can bestably fixed on the support 230, optionally, in an embodiment of thepresent application, a dispensing structure may be formed between thelens barrel 220 and the support 230, and threaded connection between thelens barrel 220 and the support 230 is fixed by means of dispensing inthe dispensing structure. For example, as shown in FIGS. 3 to 6, thedispensing structure may include a first step structure 231 formed by anupper surface of the support 230 extending downward in a peripheral areaof a threaded hole, which may provide an accommodation space for glue.Therefore, the lens barrel 220 and the support 230 can be fixedlyconnected by means of dispensing in the accommodation space provided bythe first step structure 231.

It should be understood that the first step structure 231 may includeone or more steps. This is not limited by the embodiment of the presentapplication. For example, as shown in FIGS. 3 to 6, the first stepstructure 231 includes two steps.

It should also be understood that the first step structure 231 may becontinuous or discrete along the threaded hole of the upper surface ofthe support 230. This is not limited by the embodiment of the presentapplication. For example, as shown in FIGS. 3 to 6, the first stepstructure 231 presents a concave ring along the threaded bore of theupper surface of the support 230.

Optionally, in an embodiment of the present application, a lower surfaceof the support 230 may be thickened in a peripheral area of the threadedhole to increase reliability of the threaded connection between thesupport 230 and the lens barrel 220. For example, as shown in FIGS. 3 to6, a lower surface of the support 230 extends downward in a peripheralarea of the threaded hole to form a first convex structure 233, and thelens 210 is mounted in the first convex structure 233. Specifically, thefirst convex structure 233 may be continuous or discrete along thethreaded hole of the lower surface of the support 230, which is notspecifically limited in the embodiment of the present application.

Optionally, in an embodiment of the present application, a thinnerportion of the support 230 may also be thickened to enhance the strengthof the support 230. For example, as shown in FIGS. 3 to 6, the lowersurface of the support 230 is provided with a second convex structure234 formed between the first convex structure 233 and an edge of thesupport 230. Specifically, the second convex structure 234 may becontinuous or discrete in a certain direction, which is not limited inthe embodiment of the present application.

In order to ensure that the lens 210 is stably fixed in the lens barrel220, optionally, in an embodiment of the present application, astructure for preventing the lens 210 from moving upward may be providedat a barrel opening on the upper surface of the lens barrel 220. Forexample, as shown in FIGS. 3 to 6, an upper surface of the lens barrel220 extends inward at a barrel opening to form a third convex structure,and the third convex structure 222 is used for fixing the lens 210.Optionally, in another embodiment of the present application, in orderto prevent the lens 210 from moving downward, an inner side surface ofthe lens barrel 220 and the lens 210 may be fixed by an adhesiveattaching and fixing method.

Optionally, in an embodiment of the present application, the uppersurface of the third convex structure 222 may be designed as a specificstructure, such as a funnel structure or a bevel structure, so that anoptical signal reflected by a human finger from a display screen passesthrough the third convex structure 222 as much as possible, therebyincreasing the amount of signals received by the lens 210. For example,as shown in FIGS. 3 to 6, an upper surface of the lens barrel 220 isprovided with a bevel angle formed by chamfering processing at thebarrel opening such that an inner diameter of the lens barrel 220 at theupper surface is greater than an inner diameter of the lens barrel 220at the third convex structure 222.

Optionally, in an embodiment of the present application, an additionalspace for accommodating glue may be provided between an inner sidesurface of the lens barrel 220 and the lens to increase reliability ofattaching between the inner side surface of the lens barrel 220 and thelens 210. For example, as shown in FIGS. 3 to 6, an inner side surfaceof the lens barrel 220 is provided with a second step structure 223formed under the third convex structure 222, and the lens 210 is fixedin the lens barrel 220 through the second step structure 223.Specifically, the second step structure 223 could increase theaccommodation space of the glue to the largest extent.

Optionally, in an embodiment of the present application, a barrel wallof the lens barrel 220 may be further thickened to enhance the strengthof a barrel body of the lens barrel 220. For example, as shown in FIGS.3 to 6, an outer side surface of the lens barrel 220 is provided with afourth convex structure 224 formed under the third convex structure 222,and an external thread is formed on the fourth convex structure 224.With this design structure, not only the strength of the barrel body ofthe lens barrel 220 could be increased, but also the accommodation spaceof the glue could be further increased, and the lens barrel 220 could bemore stably fixed on the support 230.

Optionally, in an embodiment of the present application, an uppersurface of the lens barrel 220 may be provided with a structure for anautofocus machine to perform a focusing operation. For example, theupper surface of the lens barrel 220 extends outward in an edge area toform at least one fifth convex structure 221, and the fifth convexstructure 221 is used for rotating the lens barrel 220 to adjust adistance between the lens 210 and an imaging chip 250. It should beunderstood that the fifth convex structure 221 may be continuous ordiscrete in a certain direction, which is not limited in the embodimentof the present application. For example, as shown in FIGS. 3 to 6, atleast one fifth convex structure 221 is four protruding petals.

It should be understood that the lens 210, the lens barrel 220, and thesupport 230 may be designed with other structures in a specificimplementation. For example, as shown in FIGS. 3 to 6, the lens 210 mayalso be designed with a size mark (a) 225 of the lens 210. The lensbarrel 220 may also be designed with a size mark (A1) 236 of the lensbarrel 220 and a counterbore 235 for mounting. For example, as shown inFIGS. 3 to 6, a different manufacturer of the counterbore can use adifferent aperture and bore depth. For another example, as shown in FIG.3 and FIG. 4, the support 230 may also be designed with a hole 237 forfixing the support 230, such as a threaded fixing hole.

FIGS. 7 to 9 are schematic views of an under-screen biometricidentification apparatus 200 according to embodiments of the presentapplication. FIG. 7 is an oriented view of an under-screen biometricidentification apparatus 200 integrated with a filter, an imaging chip250, a circuit board, and an image processor 280. FIG. 8 is an orientedview of the filter 260, the imaging chip 250, the circuit board, and theimage processor 280 in the under-screen biometric identificationapparatus 200 shown in FIG. 7. FIG. 9 is a partial schematiccross-sectional structural view of the under-screen biometricidentification apparatus 200 shown in FIG. 7 taken along C′-C′.

In embodiments of the present application, an optical signal formed byreflection of a human finger on a display screen may be used for imagingof a fingerprint image after modulation of the lens 210.

Optionally, in an embodiment of the present application, as shown inFIGS. 7 to 9, the under-screen biometric identification apparatus 200may further include an imaging chip 250 disposed under the lens barrel220 for imaging based on an optical signal passing through the lens 210,where a distance between the lens 210 and the imaging chip 250 isadjusted by rotating the lens barrel 220. In other words, the distancebetween the lens 210 and the imaging chip 250 can be adjusted byadjusting the height of the lens barrel 220.

Optionally, in an embodiment of the present application, a distancebetween an optical center of the lens 210 and an upper surface of theimaging chip 250 is equal to an imaging distance of the lens 210.Specifically, in the process of assembling the under-screen biometricidentification apparatus 200, adjustment of the distance between thelens 210 and the imaging chip 250 can be achieved by an auto-focusingmachine adjusting a height of the lens barrel 220, so as to achievedesired imaging of a fingerprint image.

Optionally, the imaging distance of the lens 210 may be greater than afocal length of the lens 210.

It should be understood that the distance between the lens 210 and theimaging chip 250 may be the distance between the optical center of thelens 210 and the upper surface of the imaging chip 250, and the opticalcenter of the lens 210 is a special point in the lens 210, where apropagation direction of light does not change as long as the lightpasses through the special point. The optical center of the lens 210 isalso referred to as an optic center of the lens 210.

In the embodiments of the present application, the imaging chip 250receives the optical signal modulated by the lens 210 and acquires abiometric detection signal (such as a fingerprint image) based on thereceived optical signal, and the biometric detection signal is used forfingerprint recognition. In other words, the imaging chip 250 firstreceives the optical signal modulated by the lens 210 and performsimaging based on the received optical signal to generate a fingerprintimage; then, the fingerprint image is transmitted to an image processorso that the image processor performs image processing to obtain afingerprint signal; and finally, fingerprint identification is performedon the fingerprint signal through an algorithm.

Optionally, in an embodiment of the present application, theunder-screen biometric identification apparatus 200 may further includea circuit board for transmitting a signal. For example, as shown inFIGS. 7 to 9, the circuit board may be a flexible printed circuit (FPC)270.

The imaging chip 250 can be soldered to the FPC 270 through a pad, andachieve electrical interconnection and signal transmission with otherperipheral circuits or other elements of the electronic device 100 asshown in FIG. 1 or FIG. 2 through the FPC 270. For example, the imagingchip 250 may receive a control signal of a processing unit of theelectronic device 100 through the FPC 270, and may also output thebiometric detection signal (e.g., a fingerprint image) to the processingunit, a control unit or the like of the electronic device 100 throughthe FPC 270.

Optionally, in an embodiment of the present application, theunder-screen biometric identification apparatus 200 may further includea steel plate fixed on a lower surface of the flexible printed circuit.

Optionally, in an embodiment of the present application, as shown inFIGS. 7 to 9, the under-screen biometric identification apparatus 200may further include an image processor 280 for receiving a biometricdetection signal (e.g., a fingerprint image) sent from the FPC 270 andperforming fingerprint identification based on the biometric detectionsignal.

Optionally, in an embodiment of the present application, as shown inFIG. 9, the imaging chip 250 is fixed on an upper surface of the FPC270, and a lower surface of the support 230 is fixedly connected to theupper surface of the FPC 270 in an edge area of the imaging chip 250.

As shown in FIGS. 7 to 9, since the support 230 is fixed on the uppersurface of the FPC 270, the support 230 and the FPC 270 can form aclosed space. And influence on stability of the under-screen biometricidentification apparatus 200 due to too large or too small pressureintensity in the closed space should be avoided.

Optionally, in an embodiment of the present application, as shown inFIGS. 7 to 9, the support 230 is provided with a vent hole 232 foradjusting an atmospheric pressure intensity of an internal space formedby the support 230 and the FPC 270.

In the embodiment of the present application, before reaching theimaging chip 250, an optical signal passing through the lens 210 mayalso be filtered by an optical filter to filter out unnecessary light.

Optionally, as shown in FIGS. 7 to 9, as an embodiment of the presentapplication, the under-screen biometric identification apparatus 200further includes an optical filter 260 which is disposed between thelens 210 and the imaging chip 250.

The filter 260 is used to reduce undesired background light infingerprint sensing to improve optical sensing of received light by theimaging chip 250. The filter 260 may be specifically used to reject theenvironment light wavelengths, such as near IR and partial of the redlight etc. For example, human fingers absorb most of the energy of thewavelengths under ˜580 nm, if one or more optical filters or opticalfiltering coatings can be designed to reject light in wavelengths from580 nm to infrared, undesired contributions to the optical detection infingerprint sensing from the environment light may be greatly reduced.

Optionally, in an embodiment of the present application, the filter 260may include one or more optical filters; the one or more optical filterscan be configured, for example, as bandpass filters to allowtransmission of the light emitted by the OLED pixels while blockingother light components such as the IR light in the sunlight. Thisoptical filtering could be effective in reducing the background lightcaused by sunlight when using the under-screen biometric identificationapparatus 200 outdoors. The one or more optical filters can beimplemented as, for example, optical filter coatings formed on one ormore continuous interfaces or one or more discrete interfaces. It shouldbe understood that the filter 260 can be fabricated on a surface of anyoptical component or along an optical path to the imaging chip 250 fromreflected light formed by reflection of a finger.

FIG. 9 merely takes an example that the filter 260 is located on anupper surface of the imaging chip 250, but the present application isnot limited thereto. For example, the filter 260 may be attached to abottom surface of a display, a surface of a prism, an interior of theimaging chip 250, or the like.

FIG. 10 is a schematic structural view of a filter 260 provided in alens barrel 220 according to an embodiment of the present application.As shown in FIG. 10, the filter 260 may be located in the lens barrel220. In such a case, in order to increase stability of the filter 260 inthe lens barrel 220, an edge area of a lower surface of the lens 210 mayextend downward to form a convex ring structure 226, a lower surface ofthe convex ring structure 226 is in contact with the filter 260, and anouter side edge area of the convex ring structure 226 is fixedlyconnected to an upper surface of the filter 260 in an adhesive attachingand fixing method.

It should be understood that the number, position and specific structureof the filter 260 shown in FIG. 9 are merely exemplary descriptions,which is not limited in this embodiment of the present application. Forexample, whether to add one or more filters 260 may be determinedaccording to actual needs of the imaging chip 250.

When the filter 260 can be located in the lens barrel 220, theunder-screen biometric identification apparatus 200 further includes: amicro lens array fixed on an upper surface of the imaging chip 250,where the micro lens array is used for imaging an optical signal passingthrough the lens 210 to imaging pixel units of the imaging chip 250.Optionally, the micro lens array includes a plurality of hemisphericallenses or prisms distributed in an array, and since the hemisphericallenses or the prisms have a condensing effect, the amount of signalreceived on the imaging chip 250 could be increased by adding a microlens array on the upper surface of the imaging chip 250.

In summary, the under-screen biometric identification apparatus 200 inthe embodiment of the present application can be compatible with andadapt to a mechanical structure of the imaging chip 250 integrated withthe micro lens array and the imaging chip 250 without the micro lensarray, and is more flexible in structure.

Optionally, in an embodiment of the present application, each of theimaging pixel units of the imaging chip 250 corresponds to one microlens of the micro lens array.

Optionally, in an embodiment of the present application, the micro lensin the micro lens array is a hemispherical lens, the imaging pixel unitis a polygon, and a diameter of the hemispherical lens is a length of along side of the polygon.

FIG. 11 is a schematic structural view of an imaging chip integratedwith a micro lens array according to an embodiment of the presentapplication. As shown in FIG. 11, when the imaging pixel unit is square,a diameter of the hemispherical lens is about a side length of thesquare. For example, both the side length of the imaging pixel unit andthe diameter of the hemispherical lens are 5 um.

It should be noted that the hemispherical lens on the imaging chip 250may have a thickness of 5 um, but a 5 um thick hemispherical lens cannotbe shown in module drawings of a millimeter thickness. That is, themicro lens array 251 shown in FIG. 10 is merely an example, and theembodiment of the present application is not limited thereto.

In other words, dimensions such as the thicknesses, lengths and widthsof various components in embodiments of the present application shown inthe drawings, as well as dimensions of the overall thickness, length andwidth of an under-screen biometric identification apparatus are merelyillustrative, and should not constitute any limitation to the presentapplication.

In an embodiment of the present application, the under-screen biometricidentification apparatus 200 is not in direct contact with the displayscreen, that is, the under-screen biometric identification apparatus 200is designed to be separate from the display screen.

Optionally, in an embodiment of the present application, the support 230in the under-screen biometric identification apparatus 200 is fixedunder a display screen by a fixing support such that a distance betweenan upper surface of the display screen and an optical center of the lens210 satisfies an imaging condition.

Optionally, in an embodiment of the present application, the imagingcondition may be the following optical imaging formula:1/u+1/v=1/f

In the formula, u denotes an object distance, v denotes an imagedistance, and f denotes a focal length. That is, the reciprocal of theobject distance plus the reciprocal of the image distance is equal tothe reciprocal of the focal length. In an embodiment of the presentapplication, a distance between an upper surface of the display screenand an optical center of the lens 210 is an object distance, and adistance between the optical center of the lens 210 and an upper surfaceof the imaging chip 250 is an image distance, and a focal length of thelens 210 is a fixed value.

In other words, when the support 230 is fixed under a display screen bya fixing support, it requires distances among an upper surface of thedisplay screen, an optical center of the lens 210 and an upper surfaceof the imaging chip 250 to satisfy the imaging condition.

Specifically, the distance between the optical center of the lens 210and the upper surface of the imaging chip 250 is the imaging distance ofthe lens 210, the imaging distance of the lens 210 can be adjusted by anauto-focusing machine adjusting a height of the lens barrel 220. Sincelight received by the imaging chip 250 may contain a fingerprint signaland an internal structure signal of a screen, in the embodiment of thepresent application, a weak alternating condition can be further formedby adjusting a focus of the lens 210, so that imaging of the internalstructure signal of the screen is blurred, while imaging of thefingerprint signal is not affected.

In other words, the image distance (i.e., the distance between theoptical center of the lens 210 and the upper surface of the imaging chip250) in the above formula can be revised. For example, a first imaginginterface is offset by a distance to a second imaging interface, and adistance between the second imaging interface and the optical center ofthe lens 210 is defined as a revised value of the image distance, wherethe first imaging interface is the clearest interface for imaging afingerprint signal, and the internal structure signal of the screenproduces an impact on the imaging of the fingerprint signal, so that thefingerprint imaging cannot meet a requirement of fingerprintidentification.

It should be understood that the first imaging interface may be offsettoward a direction close to the optical center of the lens 210, or maybe offset towards a direction away from the optical center of the lens210, which is not limited in an embodiment of the present application.For example, the first imaging interface may be offset by a distance of±10 um to ±50 um. It should be noted that the range is only an exemplaryrange of the gap, and the embodiment of the present application is notlimited thereto.

FIG. 12 is an oriented view of an upper surface of a support of anunder-screen biometric identification apparatus attached with a foamaccording to an embodiment of the present application. As shown in FIG.12, the under-screen biometric identification apparatus 200 may furtherinclude a foam 290 disposed on an upper surface of the support 230. Thefoam 290 can be used for dust seal.

In the embodiment of the present application, the under-screen biometricidentification apparatus 200 may be mounted under the display screen bybeing fixedly connected to an easily disassembled device inside aterminal device.

In other words, the above-described easily disassembled device may serveas a fixing support between the under-screen biometric identificationapparatus 200 and the display screen 320. The under-screen biometricidentification apparatus 200 can be fixedly disposed under the displayscreen in a non-contact manner by other auxiliary elements. For example,the under-screen biometric identification apparatus 200 can be fixed tothe fixing support, and fixedly disposed under the display screen 320through the fixing support.

Optionally, in an embodiment of the present application, when theunder-screen biometric identification apparatus is applied to a mobileterminal (such as a smart phone), the under-screen biometricidentification apparatus 200 may be fixed under the display screenthrough a middle frame or other components of the mobile terminal.

FIGS. 13 to 18 are schematic views of the support 230 disposed under adisplay screen 320 through a middle frame 370. As shown in FIGS. 13 to18, the under-screen biometric identification apparatus 200 can befixedly disposed under the display screen 320. The display screen 320may be the OLED display screen 120 as shown in FIG. 1 and FIG. 2, andthe under-screen biometric identification apparatus 200 may be theunder-screen biometric identification apparatus 140 as shown in FIG. 1and FIG. 2, which may specifically include the lens 210, the lens barrel220, the support 230, the imaging chip 250, the filter 260, the FPC 270,the foam 290, or the like. The under-screen biometric identificationapparatus 200 may be used for capturing a fingerprint or other biometriccharacteristics, and a biometric capturing area is at least partiallylocated in a display area of the display screen 320. As for specificstructures, functions, and biometric detection and identificationprocesses of the display screen 320 and the under-screen biometricidentification apparatus 200, reference can be made to the previousdescription of the OLED display screen 120 and the under-screenbiometric identification apparatus 140, which will not be repeatedredundantly herein.

The middle frame 370 is a frame of an electronic device that is disposedbetween the display screen 320 and a back cover and used for carryingvarious components therein, and the various components therein include,but are not limited to, a battery, a main board, a camera, a flex cable,various sensors, a microphone, an earphone, or the like.

The middle frame 370 may be made of a metal or alloy material, or evenmade of a plastic material. In this case, the middle frame 370 may evenbe integrally formed with a bezel of a mobile terminal, which means thatthe inner middle frame and the bezel serve as a whole. For example, thebezel may be just a metal welt, or a metal-like coating may be appliedto the middle frame. Further, the middle frame 370 may further be acomposite middle frame, for example, including an inner middle frame andan outer middle frame; the inner middle frame is used for carrying partsof a mobile phone (such as the support 230), while the outer middleframe is located outside the inner middle frame; and an outer edge ofthe outer middle frame is equipped with a button of the mobile phone,and the inner middle frame is integrated with the outer middle frame.

Optionally, in an embodiment of the present application, there is a gapbetween the under-screen biometric identification apparatus 200 and thedisplay screen 320.

It should be understood that there is a gap between the under-screenbiometric identification apparatus 200 and the display screen 320 inorder to enable the distance between the upper surface of the displayscreen and the optical center of the lens 210 to satisfy the imagingcondition. The size and specific meaning of the gap are not limited inthe embodiment of the present application.

For example, the gap may be determined by a manufacturer debugging in aprocess of mounting the biometric identification device 200, or may bespecified by various manufacturers.

For another example, the gap may be the distance between the uppersurface of the lens barrel 220 and the lower surface of the displayscreen 320, or may be the distance between the upper surface of thesupport 230 and the lower surface of the display screen 320.

Optionally, in an embodiment of the present application, a width of thegap between the under-screen biometric identification apparatus 200 andthe display screen 320 may be greater than or equal to a first distance,and the first distance is a minimum distance that the lens barrel 220does not touch the display screen 320 when a terminal device is in ashaking state such as a drop or a collision.

For example, the width of the gap may range from 0.3 mm to 1 mm. Itshould be noted that the range is only an exemplary range of the gap,and the embodiment of the present application is not limited thereto.

It should be understood that although the middle frame 370 being afixing support is taken as an example in the above-mentioned embodiment,in other embodiments, the under-screen biometric identificationapparatus 200 may be mounted under the display screen 320 by beingfixedly connected to any easily disassembled device in a terminaldevice, while ensuring that there is a gap between the under-screenbiometric identification apparatus 200 and the display screen 320, aslong as the under-screen biometric identification apparatus 200 can befixedly disposed under the display screen 320 in a non-contact manner.In other embodiments, the under-screen biometric identificationapparatus 200 may also be fixed on an easily disassembled device such asa back cover, a main board, a battery, or the like of the mobileterminal, and is further fixedly disposed under the display screen 320.

Since the under-screen biometric identification apparatus 200 isdisposed under the display screen 320 in a non-contact manner and is notin contact with the lower surface of the display screen 320, theunder-screen biometric identification apparatus 200 is completelydecoupled to the display screen 320, thereby avoiding damage to thedisplay screen 320 when the under-screen biometric identificationapparatus 200 is disassembled.

In addition, since the under-screen biometric identification apparatus200 is not in contact with the lower surface of the display screen 320,a fixed gap is maintained therebetween, and the gap may be an air gapthat is not filled with any auxiliary material, which could ensure thatthe under-screen biometric identification apparatus 200 does not touchthe lower surface of the display 320 when the display screen 320 ispressed or the terminal device is dropped or collided, and stability andperformance of biometric identification of the under-screen biometricidentification apparatus 200 are not affected.

In summary, in an embodiment of the present application, theunder-screen biometric identification apparatus 200 is designed to beseparated from the lower surface of the display screen 320, which couldreduce a difficulty of disassembling the under-screen biometricidentification apparatus 200, and improves maintainability of a terminaldevice. Further, complexity of mounting the under-screen biometricidentification apparatus 200 under the display screen 320 in amanufacturing process of the under-screen biometric identificationapparatus could be reduced, a manufacturing success rate of theunder-screen biometric identification apparatus could be improved, andfurther, production cost is reduced. Moreover, biometric identificationstability and performance of the under-screen biometric identificationapparatus 200 are not affected either.

Optionally, in an embodiment of the present application, as shown inFIGS. 13 to 15, the foam 290 is disposed between an upper surface of thesupport 230 and a lower surface of the middle frame 370. The foam 290can be not only used for dust seal, but also attaching the support 230and the middle frame 370.

It should be noted that, in an embodiment of the present application,the positional relationship between the display screen 320 and themiddle frame 370 is relatively fixed.

Optionally, in an embodiment of the present application, as shown inFIG. 13, an edge area of the upper surface of the middle frame 370 isattached to a lower surface of the display screen 320, and there is alsoa gap between an area of the upper surface of the middle frame 370 otherthan the edge area and the display screen 320.

The edge area of the upper surface of the middle frame 370 beingattached to the lower surface of the display screen 320 can beunderstood as: the display screen 320 and the middle frame 370 arefixedly connected to each other by means of attaching the edge of thelower surface of the display screen 320 to the edge of the upper surfaceof the middle frame 370.

In an embodiment of the present application, if the under-screenbiometric identification apparatus 200 optically performs biometricidentification, for example, optical fingerprint identification, theunder-screen biometric identification apparatus 200 needs to detectreflected light formed by reflection of a finger from an optical signalemitted by the display screen 320.

In an optional solution, as shown in FIG. 13, the middle frame 370 isprovided with a hole 371 formed in a mounting area of the under-screenbiometric identification apparatus 200, the under-screen biometricidentification apparatus 200 is disposed under the hole 371, and anoptical sensing array is disposed just opposite the lower surface of thedisplay screen 320 through the hole 371. Therefore, when theunder-screen biometric identification apparatus 200 is disposed on thelower surface of the middle frame 370, it could ensure that theunder-screen biometric identification apparatus 200 can receive theabove reflected light through the hole 371.

It should be understood that the size of the hole 371 is notspecifically limited in the embodiment of the present application. Forexample, the size of the hole 371 of the middle frame 370 may be smallerthan or equal to the size of the under-screen biometric identificationapparatus 200. For another example, the size of the hole 371 of themiddle frame 370 may also be greater than or equal to the size of thelens barrel 220.

Optionally, in an embodiment of the present application, as shown inFIG. 15, the size of the hole 371 of the middle frame 370 may be smallerthan the size of the under-screen biometric identification apparatus200.

Optionally, in an embodiment of the present application, as shown inFIG. 16, the size of the hole 371 of the middle frame 370 is greaterthan the size of the lens barrel 220, and the size of the hole 371 ofthe middle frame 370 is smaller than the size of the under-screenbiometric identification apparatus 200. In this case, the lens barrel220 can be at least partially accommodated in the hole 371 of the middleframe 370, and a buffer space can be formed between the lens barrel 220and the middle frame 370, which can ensure that the lens barrel 220 doesnot touch the middle frame 370 when the middle frame 370 is pressed or aterminal device is dropped or collided, and stability and performance ofbiometric identification of the under-screen biometric identificationapparatus 200 are not affected either.

Optionally, in an embodiment of the present application, as shown inFIGS. 17 to 18, the size of the hole 371 of the middle frame 370 may begreater than the size of the under-screen biometric identificationapparatus 200.

Optionally, in an embodiment of the present application, theunder-screen biometric identification apparatus 200 may be directlyfixed on the middle frame 370.

Optionally, in an embodiment of the present application, a side surfaceof the under-screen biometric identification apparatus 200 may befixedly connected to a hole wall of the hole 371; or an edge of an uppersurface of the under-screen biometric identification apparatus 200 maybe fixedly connected to a lower surface of the middle frame 370 in anarea located around the hole 371.

FIG. 13 and FIG. 14 are schematic structural views of the under-screenbiometric identification apparatus 200 being directly fixedly connectedto the middle frame 370. For example, as shown in FIG. 13, an edge of anupper surface of the under-screen biometric identification apparatus 200may be fixedly connected to a lower surface of the middle frame 370 inan area located around the hole 371. More specifically, for example, asshown in FIG. 14, the upper surface of the support 230 is fixedlyconnected to an area of the lower surface of the middle frame 370 thatis located around the hole 371.

In an embodiment of the present application, the manner in which theunder-screen biometric identification apparatus 200 is fixedly connectedto the middle frame 370 directly is merely an exemplary description, andthe embodiment of the present application is not limited thereto. Forexample, in other alternative embodiments, the under-screen biometricidentification apparatus 200 may also be fixedly connected to the middleframe 370 through a connector.

Optionally, in an embodiment of the present application, theunder-screen biometric identification apparatus 200 may further include:a module support 330 which may serve as a connector between the support230 and the middle frame 370 for implementing a fixed connectiontherebetween.

Optionally, in an embodiment of the present application, a side surfaceof the under-screen biometric identification apparatus 200 may befixedly connected to an inner side surface of the module support 330, oran edge of an upper surface of the under-screen biometric identificationapparatus 200 may be fixedly connected to a lower surface of the modulesupport 330; whereas an outer side surface of the module support 330 isfixedly connected to a hole wall of the hole 371, or an upper surface ofthe module support 330 is fixedly connected to an area of the lowersurface of the middle frame 370 that is located around the hole 371(i.e., at a hole edge).

FIGS. 15 to 18 are schematic structural views of the under-screenbiometric identification apparatus 200 being fixedly connected to themiddle frame 370 through the module support 330.

Optionally, in an embodiment of the present application, as shown inFIG. 15, a side surface of the under-screen biometric identificationapparatus 200 may be fixed to an inner side surface of the modulesupport 330, and an edge of an upper surface of the under-screenbiometric identification apparatus 200 and an upper surface of themodule support 330 may be simultaneously fixed to an area of the lowersurface of the middle frame 370 that is located around the hole 371(i.e., at a hole edge).

Optionally, in an embodiment of the present application, as shown inFIG. 16, a side surface of the support 230 may be fixed to an inner sidesurface of the module support 330, and an edge of the upper surface ofthe support 230 and a upper surface of the module support 330 may besimultaneously fixed to an area of the lower surface of the middle frame370 that is located around the hole 371 (i.e., at a hole edge).

Optionally, in an embodiment of the present application, as shown inFIGS. 16 and 17, the size of the hole 371 of the middle frame 370 may begreater than the size of the under-screen biometric identificationapparatus 200, and the under-screen biometric identification apparatus200 is fixed to the middle frame 370 through the module support 330.

Optionally, in an embodiment of the present application, as shown inFIG. 17, the edge of the upper surface of the under-screen biometricidentification apparatus 200 is fixed to an area of the lower surface ofthe middle frame 370 that is located around the hole 371 (i.e., at ahole edge) through the module support 330.

Optionally, in an embodiment of the present application, as shown inFIG. 18, the edge of the upper surface of the support 230 is fixed to anarea of the lower surface of the middle frame 370 that is located aroundthe hole 371 (i.e., at a hole edge) through the module support 330.

With the design structure shown in FIG. 17 and FIG. 18, the uppersurface of the module support 330 can be allowed to be higher than theupper surface of the under-screen biometric identification apparatus200. On one hand, this ensures that there is a gap between theunder-screen biometric identification apparatus 200 and the displayscreen 320. On the other hand, since the upper surface of the modulesupport 330 can be higher than the upper surface of the under-screenbiometric identification apparatus 200, the under-screen biometricidentification apparatus 200 and at least one surface of the modulesupport 330 can be fixedly connected, thereby increasing a contact areabetween the under-screen biometric identification apparatus 200 and themodule support 330, and increasing stability of fixed connection whenthe under-screen biometric identification apparatus 200 is fixedlyconnected to the module support 330 in a double-sided adhesive fixingmethod or a glue fixing method.

It should be understood that a fixed connection involved in theembodiments of the present application includes, but is not limited to,the following connection methods: a screw fixing method, a double-sidedadhesive fixing method, a glue fixing method, a welding and fixingmethod and a coupling and fixing method.

It should be understood that a main function of the module support 330is to fixedly connect the under-screen biometric identificationapparatus 200 to the middle frame 370, and allow for a gap between theunder-screen biometric identification apparatus 200 and the displayscreen 320. The position and/or specific structure of the module support330 shown in FIG. 14 are merely examples, and the embodiment of thepresent application is not limited thereto.

For example, in other embodiments, in order to increase stability of thefixing connection between the under-screen biometric identificationapparatus 200 and the module support 330, the module support 330 mayfurther be provided with a cavity structure, and the cavity structure isaligned with the hole 371 of the middle frame 370, which can provide anaccommodation space for the under-screen biometric identificationapparatus 200. In addition, the under-screen biometric identificationapparatus 200 is at least partially accommodated and fixed in the cavitystructure. For example, a side surface of the under-screen biometricidentification apparatus 200 is fixedly connected to an inner sidesurface of the module support 330 through the cavity structure.

Further, in order to ensure certain stability of fixed connection of theunder-screen biometric identification apparatus 200 and the modulesupport 330 through the cavity structure, as an embodiment, a shape ofthe cavity structure may be a shape of the under-screen biometricidentification apparatus 200. As another embodiment, the cavitystructure may be further optimized. For example, a top edge of thecavity structure of the module support 330 may extend inward to form anannular fixing part, and an edge of an upper surface of the under-screenbiometric identification apparatus 200 may be fixed to a lower surfaceof the annular fixing part, and an upper surface of the annular fixingpart is flush with an upper surface of a main body of the module support330. The annular fixing part of the module support 330 is utilized sothat the connection between the under-screen biometric identificationapparatus 200 and the module support 330 in the cavity structure can bemore stable, and in this case, the upper surface of the module support330 is higher than the upper surface of the under-screen biometricidentification apparatus 200, and a height difference therebetween canfurther increase a width of the gap between the display screen 320 andthe under-screen biometric identification apparatus 200.

In addition, the middle frame 370 of the terminal device may adopt ametal middle frame or an aluminum alloy middle frame, and a requirementfor the width of the gap between the display screen 320 and theunder-screen biometric identification apparatus 200 may not be satisfieddue to a thinner or thicker thickness of the middle frame. Therefore, inorder to ensure a sufficient width of the gap between the under-screenbiometric identification apparatus 200 and the display screen 320 in theembodiment of the present application, in an embodiment of the presentapplication, a structural design of the middle frame 370 can be furtheroptimized. The structure of the middle frame 370 in embodiments of thepresent application will be exemplarily described below with referenceto accompanying drawings.

In an actual product, if a thickness of the middle frame 370 is thinner,optionally, in an embodiment of the present application, thickeningprocessing can be performed for a mounting area of the under-screenbiometric identification apparatus 200 on the middle frame 370.

Optionally, in an embodiment of the present application, the middleframe 370 may be provided with the hole 371 formed at theabove-mentioned mounting position, and an edge of the hole 371 of themiddle frame 370 may further extend downward to form a fifth convexstructure. The under-screen biometric identification apparatus 200 maybe directly mounted or fixed to a lower surface of the fifth convexstructure through the module support 330.

Optionally, in an embodiment of the present application, as shown inFIG. 15 and FIG. 16, the edge of the hole 371 of the middle frame 370may further extend downward to form a convex ring, and the under-screenbiometric identification apparatus 200 can be located at an inner sideof the convex ring after being mounted to the middle frame 370. Further,as shown in FIG. 15 and FIG. 16, the under-screen biometricidentification apparatus 200 may also be fixed in the convex ringthrough the module support 330. On one hand, the convex ring couldensure that the middle frame 370 still has higher strength afterthinning the peripheral area of the hole 371, and on the other hand, theconvex ring could also protect the under-screen biometric identificationapparatus 200 at the inner side.

In an actual product, if a thickness of the middle frame 370 is thicker,optionally, in an embodiment of the present application, thinningprocessing can be performed for the mounting area of the under-screenbiometric identification apparatus 200 on the middle frame 370.

Optionally, in an embodiment of the present application, the lowersurface of the middle frame 370 may be provided with a groove structureformed in the periphery area of the hole 371. The under-screen biometricidentification apparatus 200 may be directly mounted or fixed to thegroove structure through the module support 330. For example, as shownin FIG. 17 and FIG. 18, the lower surface of the middle frame 370extends upward at a hole edge facing away from the display screen 320 toform a groove structure, and the under-screen biometric identificationapparatus 200 is fixed in the groove structure through the modulesupport 320.

Optionally, in an embodiment of the present application, thinningprocessing can be performed on the upper surface of the middle frame 370in the peripheral area of the hole 371. For example, as shown in FIG. 15and FIG. 16, the upper surface of the middle frame 370 is provided witha third step structure formed in an edge area of the hole 371. That is,a thickness of the middle frame 370 in the peripheral area of the hole371 is smaller than a thickness of a main body of the middle frame 370.

Optionally, in an embodiment of the present application, the heightdifference of the third step structure may also be used as a part of agap between the display screen 320 and the under-screen biometricidentification apparatus 200.

Optionally, in an embodiment of the present application, as shown inFIG. 18, an upper surface of the middle frame 370 is provided with athird step structure formed in an edge area of the hole 371, and a lowersurface of the middle frame 370 may be provided with a groove structureformed in a peripheral area of the hole 371.

Optionally, in an embodiment of the present application, as shown inFIGS. 14 to 18, chamfering processing is performed on the hole edge ofthe hole 371 of the middle frame 370 toward the display screen 320 toform a bevel angle, which can be more favorable for reflected light toenter the under-screen biometric identification apparatus 200 from thehole 371 of the middle frame 370, thereby improving biometric detectionperformance and detection efficiency of the under-screen biometricidentification apparatus.

Optionally, in an embodiment of the present application, the bevel angleextends to the hole edge on the lower surface of the middle frame facingaway from the display screen, such that the gap includes a projectionheight of a plane where the bevel angle is located in a directionperpendicular to the display screen.

Optionally, in an embodiment of the present application, as shown inFIGS. 14 to 18, when applied to a terminal device, the under-screenbiometric identification apparatus 200 may further include a cover 310.

The cover 310 may be a transparent protective cover, such as a glasscover or a sapphire cover, which may cover the display screen 120, and alower surface of the cover 310 may be attached to an upper surface ofthe display screen 320 (i.e., a display plane). The display screen 320and the cover 310 may be connected by an adhesive layer or may beconnected in other connection methods, which is not limited in thisembodiment of the present application.

Optionally, in an embodiment of the present application, as shown FIGS.13, 15 and 17, an edge of a lower surface of the display screen 320 maybe attached to an upper surface of the middle frame 370 through a foamgum 360. In this embodiment, except for providing attachment between thedisplay screen 320 and the middle frame 370, the foam gum 360 may have acertain thickness; the thickness of the foam gum 360 may allow forhaving a certain thickness between the lower surface of the displayscreen 320 and the upper surface of the middle frame 370, and thethickness of the foam gum 360 may be a part of a gap between the displayscreen 320 and the entire upper surface of the lens barrel 220. Forexample, the predetermined gap comprises a gap between a lower surfaceof the foam gum 360 and the entire upper surface of the lens barrel 220.In other word, the edge of the lower surface of the display screen 320arranged under the cover 310 is attached to the upper surface of themiddle frame 370 through the foam gum 360, and the predetermined gapcomprises a gap between the lower surface of the foam gum 360 and theentire upper surface of the lens barrel 220.

Through the foregoing analysis, it can be found that, in embodiments ofthe present application, the under-screen biometric identificationapparatus 200 is designed to be separated from the display screen 320,for example, the under-screen biometric identification apparatus 200 canbe fixed on the middle frame 370 or the back cover structure, so as tosolve problems such as disassembling difficulty, easy damage to thedisplay screen 320 and high bonding process difficulty that result fromdirectly bonding the under-screen biometric identification apparatus 200to the display screen 320 with respect to the current under-screenbiometric identification apparatus.

In addition, in the embodiments of the present application, a gap isformed between the under-screen biometric identification apparatus 200and the lower surface of the display screen 320, and the gap couldensure that the under-screen biometric identification apparatus 200 doesnot touch the lower surface of the display 320 when the display screen320 is pressed or when the terminal device is dropped or collided,thereby avoiding damage to the display screen 320.

It should be understood that FIGS. 13 to 18 are only examples in whichthe under-screen biometric identification apparatus 200 is attached tothe lower surface of the middle frame 370, and the embodiment of thepresent application is not limited thereto. For example, in otheralternative embodiments, the under-screen biometric identificationapparatus 200 may be disposed on the upper surface or interior of themiddle frame 370, and maintain a gap having a predetermined width withthe display screen 320. In a specific implementation, the upper surfaceof the middle frame 370 may be provided with a groove structure, theunder-screen biometric identification apparatus 200 may be fixed in thegroove structure, and the groove structure may be used to provide anaccommodation space for the under-screen biometric identificationapparatus 200.

In addition, alternatively, the under-screen biometric identificationapparatus 200 shown in FIG. 17 and FIG. 18 may also be mounted insidethe hole 331 of the module support 330, for example, an outer sidesurface of the under-screen biometric identification apparatus 200 maybe fixed to the inner side surface of the hole 331. In other words, theembodiments of the present application do not limit connection mannersbetween various components in the under-screen biometric identificationapparatus 200 either.

In the embodiments of the present application, the under-screenbiometric identification apparatus 200 may also be referred to as abiometric identification module. A photodetector array may also bereferred to as a photosensor array that can transmit light from lens220. For example, the photosensor array can employ an array ofphotodiodes through which an optical signal is converted into anelectrical signal so that imaging can be performed based on theelectrical signal.

In an embodiment of the present application, a biometric identificationcomponent is further provided, which may include an under-screenbiometric identification apparatus and a module support; when applied tothe under-screen biometric identification apparatus or terminal deviceas described above, the biometric identification component may bedirectly mounted to a middle frame or the fixing frame of the terminaldevice. However, when the biometric identification apparatus or theunder-screen biometric identification apparatus of the terminal deviceis damaged, the damaged biometric identification component can bereplaced, and therefore, maintenance of replacing the under-screenbiometric identification apparatus and complexity of replacing thedevice could be further reduced, thereby avoiding damage to the displayscreen.

In an embodiment of the present application, an electronic device isfurther provided, which may include a display screen and theunder-screen biometric identification apparatus in the foregoingembodiments of the present application, where the under-screen biometricidentification apparatus is disposed under a display screen such that adistance between an upper surface of the display screen and an opticalcenter of a lens in the under-screen biometric identification apparatussatisfies an imaging condition.

The electronic device can be any electronic device having a displayscreen, which implements under-screen biometric identification using atechnical solution of an embodiment of the present application. Thedisplay screen may be an organic light emitting diode display screencomprising a plurality of organic light emitting diode light sources,where the under-screen biometric identification apparatus adopts atleast a portion of the organic light emitting diode light sources as anexcitation source for biometric identification.

It should be noted that specific examples in embodiments of the presentapplication are just for helping those skilled in the art betterunderstand the embodiments of the present application, rather than forlimiting the scope of the present application.

It should also be noted that terms used in embodiments of the presentapplication and the claims appended hereto are merely for the purpose ofdescribing particular embodiments, and are not intended to limit theembodiments of the present application. For example, the use of asingular form of “a”, “the” and “said” in the embodiment of the presentapplication and the claims appended hereto are also intended to includea plural form, unless otherwise clearly indicated herein by context.

Those of ordinary skill in the art may be aware that, units of theexamples described in the embodiments disclosed in this paper may beimplemented by electronic hardware, computer software, or a combinationof the two. To clearly illustrate interchangeability between thehardware and the software, the foregoing illustration has generallydescribed composition and steps of the examples according to functions.Whether these functions are executed in hardware or software modedepends on a particular application and a design constraint condition ofthe technical solutions. Persons skilled in the art may use differentmethods to implement the described functions for every particularapplication, but it should not be considered that such implementationgoes beyond the scope of the present application.

In the several embodiments provided in the present application, itshould be understood that, the disclosed system and device may beimplemented in other manners. For example, the foregoing describedapparatus embodiments are merely exemplary. For example, division of theunits is merely logical function division and there may be otherdivision manners in practical implementation. For example, multipleunits or components may be combined or integrated into another system,or some features may be ignored or not executed. In addition, thedisplayed or discussed mutual coupling or direct coupling orcommunication connection may be indirect coupling or communicationconnection through some interfaces, apparatuses or units, and may alsobe electrical, mechanical, or connection in other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on multiplenetwork units. Part of or all of the units here may be selectedaccording to a practical need to achieve the objectives of the solutionsof the embodiments of the present application.

In addition, functional units in the embodiments of the presentapplication may be integrated into a processing unit, or each unit mayexist alone physically, or two or more than two units may be integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

If being implemented in the form of a software functional unit and soldor used as a separate product, the integrated unit may be stored in acomputer-readable storage medium. Based on such understanding, thenature of the technical solutions of the present application, or thepart contributing to the prior art, or all of or part of the technicalsolutions may be implemented in a form of software product. The computersoftware product is stored in a storage medium and includes severalinstructions for instructing a computer device (which may be a personalcomputer, a server, or a network device, and the like) to execute all ofor part of the steps of the method described in the embodiments of thepresent application. The storage medium includes: various media that maystore program codes, such as a U-disk, a removable hard disk, aread-only memory (ROM, Read-Only Memory), a random access memory (RAM,Random Access Memory), a magnetic disk, a compact disk, and so on.

The foregoing description is only a specific implementation manner ofthe present application. The protection scope of the presentapplication, however, is not limited thereto. Various modifications orreplacements may be readily conceivable to any person skilled in the artwithin the technical scope disclosed in the present application, andsuch modifications or replacements shall fall within the protectionscope of the present application. Therefore, the protection scope of thepresent application shall be subject to the protection scope of theclaims.

What is claimed is:
 1. An under-screen biometric identification apparatus, applicable to an electronic device having a display screen, comprising: a lens barrel having at least one lens unit received therein and structured to be arranged under a display screen of the electronic device without contacting the display screen, the lens unit being configured for receiving an optical signal that is generated when a human finger on the display screen is illuminated and transmitted through the display screen; a holder for holding the lens barrel, the holder being engaged to the lens barrel through a focusing thread, the focusing thread is used to adjust a distance between the lens barrel and the display screen; and an imaging chip having a size greater than the lens barrel, the imaging chip comprising an optical sensing array and being configured for implementing optical imaging based on the optical signal passing through the lens unit to obtain a biometric pattern; wherein the holder is arranged in such a manner that a predetermined gap exists between the display screen and the lens barrel, the holder provides an accommodating space under the lens barrel, the imaging chip is received in the accommodating space and out of the lens barrel, wherein the optical sensing array of the imaging chip is arranged under the lens unit of the lens barrel to receive the optical signal passing through the lens unit; wherein the under-screen biometric identification apparatus further comprises: a flexible printed circuit, wherein the imaging chip is electrically fixed on an upper surface of the flexible printed circuit, and a lower surface of the holder is fixedly connected to the upper surface of the flexible printed circuit; wherein the holder is provided with a vent hole for adjusting an atmospheric pressure intensity of an internal space formed by the holder and the flexible printed circuit.
 2. The under-screen biometric identification apparatus according to claim 1, wherein the holder is structured to be fixed to a lower surface of a middle frame of the electronic device, the middle frame is provided with a hole aligned with the lens barrel.
 3. The under-screen biometric identification apparatus according to claim 2, wherein the lens barrel is at least partially arranged in the hole of the middle frame, and a gap exists between an outer side of the lens barrel and an inner side of the hole.
 4. The under-screen biometric identification apparatus according to claim 2, wherein the holder is structured to be fixed onto the lower surface of the middle frame at a peripheral area around the hole.
 5. The under-screen biometric identification apparatus according to claim 3, further comprising a foam, wherein the foam is arranged between an upper surface of the holder and a lower surface of the middle frame.
 6. The under-screen biometric identification apparatus according to claim 3, wherein the holder comprises a pair of fixing ears, the pair of fixing ears extends from two opposite side of the holder and is configured for fixing the holder to the lower surface of the middle frame.
 7. The under-screen biometric identification apparatus according to claim 1, wherein the holder comprises a glue dispensing structure, wherein the glue dispensing structure comprises a concave groove formed around the lens barrel for providing an accommodation space for glue.
 8. The under-screen biometric identification apparatus according to claim 7, wherein the glue dispensing structure is an annular step structure comprising a step surface being parallel to an upper surface of the holder and communicated with a threaded hole of the holder, and a vertical surface connected between the upper surface of the holder and the step surface.
 9. The under-screen biometric identification apparatus according to claim 8, wherein a width of the step surface is greater than a thread depth of the threaded hole of the holder.
 10. The under-screen biometric identification apparatus according to claim 1, further comprising an optical filter, wherein the optical filter is located between the lens unit and the imaging chip and covers the optical sensing array, and comprises filtering coating layer formed on one or more continuous or discrete interfaces; the optical filter is configured to filter interference light from the optical signal, wherein the interference light comprises near IR light and partial of red light.
 11. The under-screen biometric identification apparatus according to claim 10, wherein an edge area of a lower surface of the lens extends downward to form a convex ring structure, and a lower surface of the convex ring structure is in contact with and fixed to the optical filter.
 12. The under-screen biometric identification apparatus according to claim 1, further comprising a micro lens array on an upper surface of the imaging chip, wherein the micro lens array comprises a plurality of pixel-scale micro lenses, each micro lens is formed on a pixel unit of the imaging chip respectively, is used for converging the optical signal to a corresponding pixel unit.
 13. The under-screen biometric identification apparatus according to claim 1, wherein the predetermined gap between the display screen and the lens unit is in a range from 0.3 mm to 1 mm, and the lens unit comprises an aspherical lens group cooperatively formed a macro lens with a focal length being in a range from 0.5 mm to 1.8 mm.
 14. An electronic device, comprising: a display screen; and a biometric identification apparatus arranged under the display screen, wherein a biometric acquisition area of the biometric identification apparatus is at least partially located in a display area of the display screen, wherein the biometric identification apparatus comprises: a lens barrel having at least one lens unit received therein and structured to be arranged under a display screen of the electronic device without contacting the display screen, the lens unit being configured for receiving an optical signal that is generated when a human finger on the display screen is illuminated and transmitted through the display screen; a holder for holding the lens barrel, the holder being engaged to the lens barrel through a focusing thread, the focusing thread is used to adjust a distance between the lens barrel and the display screen; and an imaging chip having a size greater than the lens barrel, the imaging chip comprising an optical sensing array and being configured for implementing optical imaging based on the optical signal passing through the lens unit to obtain a biometric pattern; wherein the holder is fixed to a lower surface of a middle frame of the electronic device in such a manner that a predetermined gap exists between the display screen and the lens barrel, the holder provides an accommodating space under the lens barrel, the imaging chip is received in the accommodating space and out of the lens barrel, wherein the optical sensing array of the imaging chip is arranged under the lens unit of the lens barrel to receive the optical signal passing through the lens unit; wherein the biometric identification apparatus further comprises: a flexible printed circuit, wherein the imaging chip is electrically fixed on an upper surface of the flexible printed circuit, and a lower surface of the holder is fixedly connected to the upper surface of the flexible printed circuit; wherein the holder is provided with a vent hole for adjusting an atmospheric pressure intensity of an internal space formed by the holder and the flexible printed circuit.
 15. The electronic device according to claim 14, wherein the middle frame is provided with a hole aligned with the lens barrel, the lens barrel is at least partially arranged in the hole of the middle frame, and a gap exists between an outer side of the lens barrel and an inner side of the hole.
 16. The electronic device according to claim 15, wherein the holder is fixed to on a lower surface of the middle frame at a peripheral area around the hole, the holder comprises a pair of fixing ears, the pair of fixing ears extends from two opposite side of the holder and is configured for fixing the holder to the lower surface of the middle frame.
 17. The electronic device according to claim 15, wherein the biometric identification apparatus further comprises a foam, wherein the foam is arranged between an upper surface of the holder and a lower surface of the middle frame.
 18. The electronic device according to claim 14, wherein the predetermined gap between the display screen and the lens unit is in a range from 0.3 mm to 1 mm, and the lens unit comprises an aspherical lens group cooperatively formed a macro lens with a focal length being in a range from 0.5 mm to 1.8 mm.
 19. An under-screen biometric identification apparatus, applicable to an electronic device having a display screen, comprising: a lens barrel having a lens unit arranged therein and structured to be arranged under a display screen, the lens unit being configured for receiving an optical signal that is generated when a human finger on the display screen is illuminated and transmitted through the display screen; a holder for holding the lens barrel and being engaged to the lens barrel, wherein the holder is structured to be fixed to a lower surface of a middle frame of the electronic device, such that the holder and the lens barrel are distanced from the display screen to maintain a predetermined gap between the display screen and the lens barrel; and an imaging chip arranged under the lens barrel and being accommodated in the holder, the imaging chip has a size greater than the lens barrel and is arranged out of the lens barrel, the imaging chip being configured for implementing optical imaging based on the optical signal passing through the lens unit to obtain a biometric pattern; wherein the under-screen biometric identification apparatus further comprises: a flexible printed circuit, wherein the imaging chip is electrically fixed on an upper surface of the flexible printed circuit, and a lower surface of the holder is fixedly connected to the upper surface of the flexible printed circuit; wherein the holder is provided with a vent hole for adjusting an atmospheric pressure intensity of an internal space formed by the holder and the flexible printed circuit. 